We all remember LW2, right? She needs to dump this guy, and we all know it. We know it instinctively, because she's unhappy, and she's not us. When it's us, we seem to operate under some kind of lame delusion that a) we've invested something priceless in our relationship, and b) it could get better.

What have you invested, exactly, that's worth risking another, what, two years, before the thing eventually dies on its own? Which it invariably will?

It's not going to get better. We all know a couple who had a terrible relationship that eventually got better, but it's almost certainly the same couple, and they [...]